The apology comes a few months after Mr. Lhota, then chairman of the Metropolitan Transportation Authority, apologized to Mayor Michael Bloomberg for referring to him as an "idiot." And that came a few weeks after Mr. Lhota apologized for a heated exchange in which he urged an authority board member to "be a man." That apology came a few months after Mr. Lhota apologized to a state senator whom he had accused of talking a lot about fighting rats in the subway, but taking no action.

So it has gone for Mr. Lhota as he has entered two high-profile roles in the past two years after spending decades behind the scenes. He has a pattern of saying impolitic things in public that lead to a backlash and an apology later.

On Tuesday, Mr. Lhota sounded as if he knew as he was speaking that what he was about to say was politically unwise.

"I don't think the Port Authority does a good enough job in anything that they do, quite honestly, but clearly in the area of security," Mr. Lhota said. "Those cops get paid more than NYPD cops, and quite honestly—I know I'm going to get into trouble for saying this—they're nothing more than mall cops."

Mr. Lhota was responding to a question about women who are trafficked through John F. Kennedy International Airport against their will into prostitution. Security for JFK is provided by the Port Authority of New York and New Jersey's police department.

On Wednesday, his campaign put out a news release in which Mr. Lhota said he apologized and that his response had been "an inappropriate answer that does not accurately reflect the hard work of its officers."

Later, when asked in an interview why he had made the remarks, Mr. Lhota responded: "I said it because I was standing in front of people who had asked me about human trafficking, one of the most disgusting things that happens in our society."

Mr. Lhota has been leading the Republican primary field in recent polls. His rivals and police unions criticized the comments Wednesday.

John Catsimatidis, a billionaire businessman, called for an apology and said of Mr. Lhota: "It's sad that the son of an NYPD lieutenant would take verbal shots at the Port Authority Police or any law-enforcement organization."

Another Republican candidate, George McDonald, criticized Mr. Lhota for demonstrating "the very same intemperate attitude" as former Mayor Rudolph Giuliani, in whose administration Mr. Lhota served.

Mr. Giuliani's administration was often at odds with the Port Authority over security at airports and sought to have the New York City Police Department take over the job. Administration officials charged that the Port Authority Police Department was incompetent. Once, Mr. Giuliani made his own disparaging comparison, saying the Port Authority's reports on snow plowing at the airport resembled those issued by the Telegraph Agency of the Soviet Union, known as TASS, the former Soviet news agency.

Indeed, recent New York City mayors stretching back to Ed Koch have made quite a few intemperate comments they later regretted—or, in many cases, didn't. But there is a difference between what voters like on the campaign trail and what they'll accept at City Hall, said George Arzt, a former press secretary for Mr. Koch who now works as a political consultant.

"Temperament is always an issue during a campaign. People look for a mature authority figure to run the city," he said. "Ed Koch, Rudy Giuliani and Mayor Bloomberg did not lose their tempers often during the campaign leading up to their election. Afterwards, they're home free."

This copy is for your personal, non-commercial use only. Distribution and use of this material are governed by our Subscriber Agreement and by copyright law. For non-personal use or to order multiple copies, please contact Dow Jones Reprints at 1-800-843-0008 or visit www.djreprints.com.